1. Field of the Invention
The present invention relates to a pixel structure of a liquid crystal display device, especially to a 3D liquid crystal display device and a pixel structure thereof.
2. Description of the Related Art
With reference to FIG. 1, in a conventional 3D display system, images from a liquid crystal display panel of the 3D display system will first travel through a polarizer 90 so as to turn into linearly polarized images. The linearly polarized images then travel through a λ/4 patterned retarder plate 91. The λ/4 patterned retarder plate 91 has a plurality of first phase retarder rows 910 and a plurality of second phase retarder rows 911 and can convert the linearly polarized images into left-handed circularly polarized images and right-handed circularly polarized images and use the left-handed circularly polarized images and right-handed circularly polarized images as left-eye input images and right-eye input images, respectively. A pair of polarized glasses 8 worn by an observer has two lenses, both of which are composed of a quarter-wave plate 80 and a polarizer 81. The images including the left-handed circularly polarized images and right-handed circularly polarized images first travel through the quarter-wave plates 80 of the lenses to be converted into linearly polarized images, then travel through the polarizers 81 of the lenses and arrive at the left and right eyes of the observer, respectively. Because the polarizers 81 of the lenses have different polarization directions, the user's left eye can only see the left-eye input images and the right eye can only see the right-eye input images. Hence, it can achieve a three-dimensional effect.
Furthermore, the pixel structure of the liquid crystal display device can be divided into single-gate pixel structure and tri-gate pixel structure according to the driving type of the pixel structure. With reference to FIGS. 2, 3 and 6, FIG. 2 is a schematic view of a pixel arrangement of a conventional liquid crystal display device having a single-gate pixel structure; FIG. 3 is a schematic view of pixel arrangement of a conventional liquid crystal display device having a tri-gate pixel structure; FIG. 6 is a schematic view of a conventional tri-gate pixel structure. As shown in FIG. 2, a plurality of sub-pixel regions 600, 601, 602 of a pixel unit 60 of a single-gate pixel structure 6 are arranged along a length direction of a gate line; and as shown in FIG. 3 and FIG. 6, a plurality of sub-pixel regions 500, 501, 502 of a pixel unit 50 of a tri-gate pixel structure are arranged along a length direction of a data line, and there are pixel electrodes 52R, 52G, 52B respectively mounted in those sub-pixel regions 500, 501, 502 and respective correspond to photoresists with different colors. Under the same resolution, comparing the liquid crystal display device having the single-gate pixel structure 6, the number of gate lines 710 of the liquid crystal display device having the tri-gate pixel structure 5 is increased by three times, and the number of data lines 700 of the liquid crystal display device is decreased by three times, hence a gate driver 71 of the liquid crystal display device having tri-gate pixel structure will use more gate driving chips and a source driver 70 thereof will use less source driving chips. Since the manufacturing cost and power consumption of the gate driving chips are relatively lower, therefore using tri-gate pixel structure can reduce the manufacturing cost and power consumption of the liquid crystal display device.
However, when the tri-gate pixel structure 5 in FIG. 3 is used in a 3D liquid crystal display device, the 3D liquid crystal display device will have a color washout problem occurring at top and bottom view angles. With reference to FIG. 4, when an observer wearing a pair of polarized glasses to see the screen of the device through the first phase retarder rows 910 and the second phase retarder rows 911 of a quarter-wave plate 9 from a horizontal view angle, a top view angle or a bottom view angle, the color-mixing effect received by the eyes of the observer will have different color-mixing effects. For example, in FIG. 5A, under a horizontal view angle, the colors of the sub-pixels of the pixel structure seen by the observer through the second phase retarder row 911 are arranged in an order of R, G, B; in FIG. 5B, under a top view angle (from top to bottom), the colors of the sub-pixels of the pixel structure seen by the observer through the second phase retarder row 911 turn to be arranged in an order of G, B, R. Because the first phase retarder rows 910 and the second phase retarder rows 911 are used to form the left-eye and right-eye input images, the first phase retarder rows 910 and the second phase retarder rows 911 corresponding to the wrong pixel structures will lead to a color washout problem.
Therefore, it is necessary to provide a 3D liquid crystal display device and a pixel structure thereof to overcome the problems existing in the conventional technology.